function y = jen_sampson(x)
%Jennrich and Sampson function
%n=2,m>=n,x0=[0.3,0.4] ????????????m=10
%fmin1=f6([0.2578;0.2578])=124.362 for m=10
%Author:Ji Lin
y=ones(1,10);
for ii=1:10
    y(ii)=2+2*ii-(exp(ii*x(1))+exp(ii*x(2)));
end
y=sum(y.^2);